Textile material containing organic esters of cellulose and method of preparing the same



' Patented Aug. 11, 1931 UNITED STATES PATENT o FmE CAIILLE DBEY I'UB AND WILLIAM B. BLUME, OF NEW- YORK, N. Y., ASSIGNOBS IO WEBB GORIORATION OF AMERICA, A. CORPORATION OF DELAWARE .ZEEZ'I'ILE MATERIAL CGNTAIHIHG ORGANIC ESTERS OI CELLULOSE AND METHOD IBEPARING THE SAME no Drawing.

This invention relates to the treatment of fabrics or yarns containing organic esters of cellulose in such a manner that the fabrics or yarns may be safely ironed by means of irons or calenders that are at higher temperatures than may safely be employed with previously known textile materials.

An object of ourinvention is to produce textile material containing organic esters of cellulose that have higher safe ironing temperatures than prev1ously' known textile materials of this type. Other objects of our invention will a pear from the following detailed description. 7

extile materials containing yarns of 'organic esters of cellulose may ordinarily not be ironed with an iron whose temperature is above about 230 0. since the organic esters of cellulose material tends to stick to the :0 iron above this temperature. To increase the safe ironing point of such textile materials, it has been proposed to partially saponify the same, and it has also been proposed to weight these textile materials with 26 metallic salts. In either case, however,the

safe ironing point is raised to a predetermined amount, which, in the case of cellulose acetate textile material, does not generally exceed 260 C. We have made the so surprising discovery that'if textile materials -containing organic esters of cellulose are first partially saponified and then weighted with a metallic salt or other weightin agent the safe ironing oint of the materia is increased considerably, so that these materials may be ironed at temperatures above that at which even cotton or silk scorches. Thus, a fabric containing cellulose acetate yarn, when treated in accordance with our invention, has a safe ironing point of 27 5 to 285 C. or more. I

In accordance with our invention, we partially saponify the textile material, made of or containing organic esters of cellulose by means of an alkaline bath of suitable concentration and at suitable temperatures.

The so partially saponified material is then weighted with metallic salts or other weightin agents to the desired degree.

' he textile material to be treated in acsilicate, or tri-sodium Application filed July 18, 1928. Serial No. 293,781.

cordance with our invention may be a woven, knitted or netted fabric or it may be yarn in the form of hanks, or wound on bobbins, cones or other textile packages.

Thetextile' material to be treated may contain any suitable organic ester of cellulose such as cellulose acetate, cellulose formate, cellulose propionate or cellulose butyrate. The textile material may consist wholly of one or more of these organic esters of cellulose, or may be a mixed fabric or yarn containing yarns of these organic esters of cellulose and yarns of cotton, silk or reconstituted cellulose (rayon).

The alkaline'bath used for partially saponifying the cellulose acetate contained in the fabric or yarn may be either of low concentration or of highconcentration dependin on the temperature of treatment. If an a alinesolution of low concentration is used, higher temperatures may be employed in the process, .whereas if alkaline solutions of high concentrations are used, low temperatures of treatment are employed. If a solution of intermediate concentration is employed, intermediate temperatures of treatment should .be used.

The saponifying bath may contain any suitable alkali or alkaline salt for producing hydroxyl ions in aqueous solutions. Of the alkalies that are suitable, sodium hydroxide, potassium hydroxide or ammonium ide may be mentioned. Examples 0 alkaline salts. are sodiumor potassium carbonates,- sodium or potassium henolate, sodium or potassium sulphite, sodium or potassium phosphate. In order to promote intense sur ace saponification of the yarn containing the or anic ester of cellulose, buffer salts or mo ifying agents such as soap, sodium acetate, borax or alcohol, etc. may be added to the saponifying hydroxyl ions in amounts corresponding to less than 0.2 grams of sodium hydroxide per liter. The saponification may proceed to any desired extent, say 3% or- 5 to 10% or more. These percentages represent the percent of loss of weight the cellulose acetate has suffered through the saponification treatment.

.The saponification of the fabric with alkaline solutions of low concentrations may be carried out in a tank, on the jig, on the winch or in any other suitable device. Often it is desirable to thoroughly wet out the fabric rior to subjecting it to the saponifiqation ath. The addition of soap to the saponification bath is of great advantage in promoting level saponification of the organic esters of cellulose material, and also the presence of the soap in the saponifying bath tends to help to cause the saponification to be concentrated on the surface of the yarn containing the organic esters of celulose, which causes desirable increase in safe ironing point. While the proportions of soap to the solution may be varied within wide limits, it may be stated that the presence of 0.5 grams to 10 grams of soap per liter of solution produces satisfactory results.

In one mode of carrying out the partial saponification with the use of solutions contaming alkali in low concentrations, the goods are scoured in an open'bath on strings or in any suitable machine such as a jig, with a bath containing olive oil soap for an hour or two. The goods may then be removed from the bath and saponified in a separate bath containing fresh water and alkali, but'they are preferably saponified dire tly in the general scouring bath by the addition of a requisite amount of caustic soda. In one mode of partially saponifying the fabric containing the organic ester of cellulose with an alkaline solution of low concentration, the fabric 'is immersed in a bath of such large volume that it contains sufficient alkali to cause the desired degree of saponification-but which is not of such concentration to exceed the maximum permis- 54% acetyl value, we have found that a bath of up to 120 to 180 times the weight of the fabric can advantageously be used, and that such a bath should preferably contain an amount of caustic soda to the extent of 4 to 8% of the weight of the fabric, when a bath temperature of C. is used. Obviously,

if the fabric or yarn contains other organic esters of cellulose or an alkaline material other than caustic soda is used or if the temperature of the bath is other than 80 Q, the proportions will be varied accordingly. Likewise it is apparent that when smaller amounts of alkaline material are used the volume of the saponification bath may be correspondingly decreased.

In another mode of carrying out the saponification when alkaline-solutions of low concentrations are employed, the fabric or yarn containing the yarns of cellulose acetate is treated in an alkaline bath of comparatively small volume and containing a relatively small amount of caustic soda. As the saponification proceeds, further quantities of caustic soda are added in small increments, until the desired degree of saponification has taken place. Until the operator has gained sufficient experience, it is preferable to check up the amount of caustic soda in thebath by titration with sulphuric acid to insure that the amount of 9 caustic soda added is not sufiiclent to cause fabric containing the organic esters of cellulose in any suitable manner. However, we prefer to apply the caustic sodawhen ap-' plied in comparatively concentrated solution to the fabric by padding the caustic solution onto the fabric and then permitting the same to stand for an appreciable length of time. The temperature of treatment is preferably room temperature and should not exceed 35 C. for obtaining the best results.

The textile material after saponification by any of the above-methods, is then weighted by subjecting the same to a swelling agent and a weighting agent. Thelswelling agent and the weighting agent may be applied in separate baths or they may be applied in the same bath. Furthermore the weighting agent may of itselfbe a swelling agent so that the use ofanother swelling agent may not be necessary. Examples of threeuarters of an hour.

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swelling agents are comparatively concentrated aqueous solutions of acetic acid,-formic acid, lactic acid, or acetone. Examples of weighting agents are aqueous solutions of stannic chloride or tannic acid, strong solutions of which are also swelling agents. After treating with the weighting agent, the fabric is subjected to the action of a fixing bath which contains alkaline phosphates or silicates.

The product formed by our process has a safe ironing point that is from 10 to 25 C. or more higher than the safe ironing point of the textile materials that have been saponified alone or have been weighted alone. Moreover, the fabric produced by our process has a softer hand than fabrics that have been subjected to the weighting process alone or to the partial saponification process alone.

For the best results, the textile material should be first partially saponified and then weighted, rather than first weighted and then partially saponified, since a much higher safe ironing point. may be imparted to the textile material by the process that involves first partially saponifying and then weighting. While we do not limit ourselves to this theory we believe that this is due to the fact that if the textile material is first weighted, the presence of the weighting agent causes saponification to proceed throughout the whole fabric, as against the intense surface saponification produced by the partial saponification of the unweighted textile material by the process above described.

In order to further illustrate our invention thefollowing detailed example is given, but this invention is not limited thereto.

Ewample A wovenfabric consisting wholly of cellulose acetate yarn is plaited and strung, and isthen immersed in a bath in which the ratio of water to fabric is between 130 and 160 to 1. This bath contains soap to the extent .of 1 gram per liter of bath and the bath temperature is maintained at 80 C. The fabric is treated in this soap bath for It is then raised out o the bath, and caustic soda in an amount equal to 6% of the weight of the fabric is added to the bath, and after the solution is homogeneous, the fabric is then immersed in the bath and is treated therein for approximately threehours while the bath temperature is maintained at 80 C. The fabric is then lifted and washed off in water at C.

- The so partially saponified fabric is thenv solution of stannic chloride for "one-halfoff in water and then treated with a 7 Tw.

solution of. sodium silicate. The fabric is then washed with or without soap, and is found to have increased in weight by 20%.

If desired, this fabric may be dyed or.

printed. The safe ironing point of the fabric has been increased by this process by 60 C.

or more, as is'indicated by the fact that the safe ironing point of the fabric, after it has been treated as above described, is increased to 280 'C. to 285 C. The safe ironing point is determined by measuring the maximum temperature of an iron that does not stick to, melt or scorch the fabric when said iron is permitted to rest upon the fabric for five seconds. The safe ironing point of a cotton fabric when tested in 7 this manner is not appreciably over 260 C.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the. spirit of this invention.

Having described our invention, what we lose acetate comprising both partially saponifying the cellulose acetate and weighting the textile material.

3. Method of increasing the safe ironing point of a textile material containing organic esters of cellulose comprising subjecting the textile material to a solution of alkali and thenweighting the same.

4. Method of increasing the safe ironing point of a textile material containing organic esters of cellulose-comprising subjecting the textile material to a solution of alkali and then weighting the same with a tin compound.

5. Method of increasing the safe ironing point of a textile material containing organic esters .of cellulose comprising subjecting the textile material to a solution of'alkali and then weighting the same with a tannic.

acid compound.

6. Method of increasing the safe ironing point of a textile material containing organic esters of cellulose comprisingsubjecting the textile material to a solution of alkali, then Weighting the same by treatment with a tin salt, and then 'fixing the tin by treatment with a precipitating agent, whereby a textile material having a safe ironing point above 270 C. is produced.

7. Method of increasing the safe ironing hour at 55 to 65 C. The fabric is rinsed point of a textile material containing celluloseacetate comprising subjecting the textile material to a solution of alkali and then weightin the same.

8. Met od of increasing the safe ironing point of a textile" material: containing cellulose acetate comprising subjecting the textile material to a solution "of alkali and then weightin the same with a tin compound.

9. Met 0d of increasing the safe ironing point of a textile material containing cellulose acetate comprising subjecting the textile material to a solution of alkali, then weighting the same by treatment with a tin salt, and then fixing the tin by treatment with a precipitating agent, whereby a textile material having a safe ironing point above 270 C. is produced. v

10. Method'of increasing the safe ironing point of a textile material containing cellu lose acetate comprising'subjectin the textile material to a solution of alkali, t en weight ing the same by treatment with a tannic acid solution, and then fixing thetannic acid compounds by treatment with a precipitating agent, whereby a textile material having a safe ironing point above 270 .C. is produced.

11. A textile material containing par-' tially saponified organic esters of cellulose, which'textile material is weighted with a weighting agent.

' 12.- A textile material'containing partially saponified cellu'lose acetate, which textile material is weighted 'with a weighting agent.

- 13. A textile material containing artially saponified organic estersof cell ose, which textile material is weighted with a tin compound.

14. A textile material containing partially saponified organic esters of cellulose, which textile materlal is weighted with a tannic acid compound.

15; A textile material containing partially saponified cellulose acetate, which textile material is weighted with a tin compound.

16. A textile material containing partially saponified cellulose acetate, which textile material isv weighted with a tin compound, saidtextile material having a safe ironing point above 270 C.

17. A textile material containing partially saponified cellulose acetate, -which" textile material is weighted with a tannic acid compound, said textile material having a safe ironing point above 270 C.

18. A textile material containing partially saponified cellulose acetate, which textile material is Weighted with a tin compound,

- said textile material having a safe ironing point between 280 and 285 C.

In testimony whereof, We have hereunto subscribed our names.

CAMILLE DREYFUS. WILLIAM R. BLUME. 

